207 research outputs found

    Structure of Extremely Nanosized and Confined In-O Species in Ordered Porous Materials

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    Perturbed-angular correlation, x-ray absorption, and small-angle x-ray scattering spectroscopies were suitably combined to elucidate the local structure of highly diluted and dispersed InOx species confined in porous of ZSM5 zeolite. These novel approach allow us to determined the structure of extremely nanosized In-O species exchanged inside the 10-atom-ring channel of the zeolite, and to quantify the amount of In2O3 crystallites deposited onto the external zeolite surface.Comment: 4 pages, 5 postscript figures, REVTEX4, published in Physical Review Letter

    Appearance of room temperature ferromagnetism in Cu-doped TiO2δ_{2-\delta} films

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    In recent years there has been an intense search for room temperature ferromagnetism in doped dilute semiconductors, which have many potentially applications in spintronics and optoelectronics. We report here the unexpected observation of significant room temperature ferromagnetism in a semiconductor doped with nonmagnetic impurities, Cu-doped TiO2_2 thin films grown by Pulsed Laser Deposition. The magnetic moment, calculated from the magnetization curves, resulted surprisingly large, about 1.5 μB\mu_B per Cu atom. A large magnetic moment was also obtained from ab initio calculations using the supercell method for TiO2_2 with Cu impurities, but only if an oxygen vacancy in the nearest-neighbour shell of Cu was present. This result suggests that the role of oxygen vacancies is crucial for the appearance of ferromagnetism. The calculations also predict that Cu doping favours the formation of oxygen vacancies.Comment: 4 pages, 3 figures, published in Phys. Rev. B (Rapid Comm.

    Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes.

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    OBJECTIVES: The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND: Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS: The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS: Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS: Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.info:eu-repo/semantics/publishedVersio

    Prevalence, risk factors, and identification of Salmonella spp. in stray dogs of northwest Mexico

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    Salmonellosis has a worldwide relevance in aspects associated with public health, as only in 2009 were reported 93.8 million cases in humans. The objective of the study was to establish the prevalence, risk factors and bacteriological and molecular identification of Salmonella spp in stray dogs in urban, rural and coastal areas of Mexicali, a city in northwest Mexico. From May 2014 to February 2015, 385 dogs were tested. Sampling was performed by rectal swab and conventional bacteriological techniques were applied, for later implementation of the API 20E system and molecular identification by polymerase chain reaction (PCR). The data were analysed statistically by means of descriptive statistics and multiple logistic regression modelling. A prevalence of 6.27% was obtained in the dogs examined, the samples obtained were characterised to subspecies (Salmonella enterica subspecies enterica and Salmonella enterica subspecie arizonae). The geographical region with the highest prevalence in the study was the coast (10%), followed by the rural area (8.57%) and the urban area (5.8%), however, no significant statistical differences were detected. There was significant difference in the prevalence by age of dogs under one year (P&lt;0.05). The identification of Salmonella in dogs from northwest Mexico could correspond to serovars of zoonotic importance indicating a potential risk for the population

    Characterization of source rocks and groundwater radioactivity at the Chihuahua valley

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    As part of a scientific research project about alpha radioactivity in groundwater for human consumption at the Chihuahua City, the charac-terization of rock sources of radioactivity around de Chihuahua valley was developed. The radioactivity of groundwater and sediments wasdetermined, too. The radioactivity of uranium- and thorium- series isotopes contained in rocks was obtained by high resolution gamma-rayspectroscopy. Some representative values are 50 Bq/kg for the mean value of Bi-214 activity, and 121.5 Bq/kg for the highest value at Westof the city. The activity of sediments, extracted during wells perforation, was determined using a NaI(Tl) detector. A non-reported beforeuranium ore was localized at the San Marcos range formation. Its outcrops are inside the Chihuahua-Sacramento valley basin and its activ-ity characterization was performed. Unusually high specific uranium activities, determined by alpha spectrometry, were obtained in water,plants, sediments and fish extracted at locations close to outcrops of uranium minerals. The activity of water of the San Marcos dam reached7.7 Bq/L. The activity of fish, trapped at San Marcos dam, is 0.99 Bq/kg. Conclusions about the contamination of groundwater at North ofChihuahua City were obtained.Como parte de un proyecto cient ́ıfico sobre actividad alfa en agua subterr ́anea de consumo humano en la ciudad de Chihuahua, se hadesarrollado la caracterizaci ́on de las rocas fuentes de la radiactividad en el valle de Chihuahua. Se determin ́o tambi ́en la actividad de muestrasde agua subterr ́anea y de sedimentos. La actividad de los is ́otopos de las series radiactivas en las rocas se obtuvo usando espectroscop ́ıagamma de alta resoluci ́on. Algunos valores representativos son 50 Bq/kg para el valor medio de la actividad del Bi-214 y 121.5 Bq/kg para elvalor m ́as alto al oeste de la ciudad. La actividad de los sedimentos extra ́ıdos durante la perforaci ́on de pozos para agua potable, se determin ́ousando un detector de NaI(Tl). En la formaci ́on monta ̃nosa de San Marcos se localiz ́o un dep ́osito de uranio no publicado. Sus afloramientosse encuentran dentro de la cuenca del valle Chihuahua-Sacramento y se realiz ́o la caracterizaci ́on de su radiactividad. Se determinaronactividades por espectrometr ́ıa alfa de agua, plantas, sedimentos y peces extra ́ıdos en emplazamientos cercanos a los afloramientos deminerales de uranio. La actividad del agua en la presa de san Marcos lleg ́o a 7.7 Bq/L. La actividad de pescados de la misma presa alcanza0.99 Bq/kg. Se obtuvieron conclusiones sobre la contaminaci ́on del agua subterr ́anea al norte de la ciudad de Chihuahua

    Small-Bowel Obstruction Secondary to Ileal Trichobezoar in a Patient with Rapunzel Syndrome

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    Bezoars are conglomerations of undigested foreign material retained in the gastrointestinal tract. Trichobezoar is a compact conglomeration of swallowed hair and constitutes less than 6% of all bezoars. Their most frequent location is in the stomach but they may extend through the pylorus into the small bowel. This condition is known as Rapunzel syndrome. Many patients may remain asymptomatic or present a mild form of the disease characterized by abdominal pain, early satiety, nausea, and vomiting. Complications may manifest as gastric outlet obstruction or bleeding, and intestinal obstruction. A 15-year-old female patient presented with clinical findings of intestinal obstruction. The patient suffered from depressive and anxiety disorders and trichotillomania, although trichophagy could not be assured. Alopecia circumscripta and irregular hair length on the scalp were identified. A computed tomography (CT) scan showed two images highly suggestive of trichobezoars, one in the stomach and the second one causing obstruction at the ileocecal valve. At laparotomy, both a mobile gastric trichobezoar with a tail extending to the duodenum and a trichobezoar causing obstruction at the ileocecal valve were removed. The postoperative course was uneventful. The passage of a detached trichobezoar fragment in a patient with Rapunzel syndrome may cause intestinal obstruction. CT is the preferred image modality for the evaluation of suspected trichobezoars in order to characterize their size and locations, the presence and level of obstruction, and complications such as ischemia or perforation. A case of small-bowel obstruction secondary to ileal trichobezoar in a patient with Rapunzel syndrome is herein reported

    The Degree and regularity of vanishing ideals of algebraic toric sets over finite fields

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    Let X* be a subset of an affine space A^s, over a finite field K, which is parameterized by the edges of a clutter. Let X and Y be the images of X* under the maps x --> [x] and x --> [(x,1)] respectively, where [x] and [(x,1)] are points in the projective spaces P^{s-1} and P^s respectively. For certain clutters and for connected graphs, we were able to relate the algebraic invariants and properties of the vanishing ideals I(X) and I(Y). In a number of interesting cases, we compute its degree and regularity. For Hamiltonian bipartite graphs, we show the Eisenbud-Goto regularity conjecture. We give optimal bounds for the regularity when the graph is bipartite. It is shown that X* is an affine torus if and only if I(Y) is a complete intersection. We present some applications to coding theory and show some bounds for the minimum distance of parameterized linear codes for connected bipartite graphs

    Media control: a case for privatization in transitional economies

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    The television market can be one of the most dynamic industries if country-specific regulations allow for private competitors to enter the market. The entry of competition changes the market from monopolistic to oligopolistic, which has positive performance implications for the industry. Our research analyzes the development of the Croatian TV market from the monopolistic stage to the current oligopolistic stage. Econometric models in this article aim to estimate the current trend of market concentration and its future potential. The authors’ research focusing on the industry from a market concentration perspective provides guidance for the practitioner in regard to profitable investment opportunities. They also illustrate for other transitional economies that to move toward a “free” society, media must be free from government control which will evolve rapidly once privatized. © 2016 Taylor & Francis

    Concentración de anticuerpos contra proteínas de las glándulas salivales de Aedes aegypti e historia de la exposición al virus del dengue en residentes de una zona endémica colombiana

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    Introduction: Mosquito salivary proteins are able to induce an antibody response that reflects the level of human-vector contact. IgG antibodies against dengue virus (DENV-IgG) are indicators of previous exposure. The risk of DENV transmission is not only associated to mosquito or dengue factors, but also to socioeconomic factors that may play an important role in the disease epidemiology.Objective: To determine the effect of the presence of Aedes aegypti mosquitos in different stages in households and the history of dengue exposure on vector-human contact determined by the level of anti-salivary protein antibodies in people living in a Colombian endemic area.Materials and methods: A pilot study of 58 households and 55 human subjects was conducted in Norte de Santander, Colombia. A questionnaire for socioeconomic factors was administered and houses were examined for the presence of Ae. aegypti specimens in the aquatic stages. The level of DENV-IgG antibodies (DENV-IgG), in addition to IgG and IgM anti-Ae. aegypti salivary gland extract (SGE) antibodies (SGE-IgG, SGE-IgM) were evaluated by ELISA using blood collected in filter paper.Results: We found a significant higher level of SGE-IgG antibodies in subjects living in houses with Ae. aegypti in aquatic stages. We also found a higher concentration of SGE-IgG antibodies in people exposed to DENV, a positive correlation between IgM-SGE and IgG-DENV and a negative correlation with IgG-SGE.Conclusion: Anti-salivary proteins antibodies are consistent with the presence of Ae. aegypti aquatic stages inside houses and DENV-IgG antibodies concentrations.Introducción. Las proteínas salivales de los mosquitos son capaces de inducir la producción de anticuerpos, lo que a su vez refleja el grado de contacto hombre-vector. Además, los anticuerpos IgG contra el virus del dengue son indicadores de una exposición previa a este virus. El riesgo de transmisión del virus del dengue está asociado no solo con factores relacionados con la biología del mosquito, o factores virales, sino también, con factores socioeconómicos, como la disponibilidad de agua en el hogar, que pueden desempeñar un papel importante durante la temporada epidémica.Objetivo. Determinar el efecto de la presencia de mosquitos Aedes aegypti en las casas y la exposición previa al virus del dengue, sobre los niveles de anticuerpos contra mosquitos en el contacto humano-vector en habitantes de un área endémica de Colombia.Materiales y métodos. Se hizo un estudio piloto de 58 casas y 55 participantes en Norte de Santander, Colombia. Se empleó un cuestionario para recopilar la información sobre los factores socioeconómicos y se examinaron las casas para detectar la presencia de sitios de cría de Ae. aegypti. Se recolectó una muestra de sangre humana total en papel de filtro y se estableció el nivel de anticuerpos IgG contra el virus del dengue, además del de los anticuerpos IgG e IgM anti-Ae. aegypti de extracto de glándula salival mediante ELISA.Resultados. Los resultados revelaron un mayor nivel de anticuerpos IgG de extracto de glándula salival en sujetos que vivían en casas con presencia de mosquitos Ae. aegypti en la fase acuática. Asimismo, se encontró una mayor concentración de anticuerpos IgG de extracto de glándula salival en personas previamente expuestas al virus del dengue. Los resultados evidenciaron una correlación positiva significativa entre los niveles de IgM de extracto de glándula salival y los de IgG anti-virus del dengue de extracto de glándula salival, y una correlación negativa con los de IgG de extracto de glándula salival , aunque esta última no fue significativa.Conclusión. La concentración de anticuerpos fue mayor en quienes vivían en casas con estadios acuáticos de Ae. aegypti, como también en las personas con anticuerpos IgG anti-virus del dengue
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